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Asteroids keep their rings safe from gas giants’ clutches

If an asteroid acquires rings, it's likely to hang on to them – so more space rocks may have rings than we thought. If only we knew how they got there

HOLD on to your belts. Asteroids cling on to their rings despite the prying gravity of giant gas planets.

In 2014, astronomers spotted rings around a large asteroid called Chariklo, which orbits in the chaotic region between Saturn and Uranus. “It’s like pinball: the rings hit Saturn, they go around Neptune,” says Othon Winter of Sao Paulo State University, Brazil.

Rings are unstable, so to find out if Chariklo’s would survive, Winter and colleagues simulated 729 objects just like the asteroid. In more than 90 per cent of cases the rings remained intact, despite an average of 150 close encounters with giants (Astrophysical Journal, doi.org/bj44).

The next step is to find out where Chariklo’s ring came from.

This article appeared in print under the headline “Rings are safe around asteroids”